CLN: Use C-API for datetime.date

[ShaharNaveh]

• closes #xxxx
• tests added / passed
• passes black pandas
• passes git diff upstream/master -u -- "*.py" | flake8 --diff
• whatsnew entry

[jbrockmendel]

LGTM pending green

[TomAugspurger]

For my own understanding, why do we prefer to use the C API? Is this likely to improve performance?

[ShaharNaveh]

Is this likely to improve performance?

@TomAugspurger Correct!

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This is because when we use import and not cimport we are going through the python space, which is slower than pure C.

I have made POC so you could see to diffs:

Both are doing the exact same thing, only that the C-API datetime.date is much faster.

[WillAyd]

I think can just cimport cpython.datetime as datetime to minimize changes no? Didn't we move away from the import pattern here already in #32459

[ShaharNaveh]

Good catch!

Somehow slipped away from me

[WillAyd]

lgtm

[mroeschke]

Thanks @MomIsBestFriend